what does anti-virus software do?

What does anti-virus software do?
Although details may vary between packages, anti-virus software scans files or your computer's memory for certain patterns that may indicate an infection. The patterns it looks for are based on the signatures, or definitions, of known viruses. Virus authors are continually releasing new and updated viruses. So it is important that you have the least definitions installed on your computer.
Once you have installed an anti-virus packages, you should scan your entire computer periodically.
# Automatic scans- depending what software you choose you may be able to configure it to automatically scan specific files or directories and prompt you at set intervals to perform scans.
# Manual scans - It is also a good idea to manually scan files you receive from an outside source before opening them. This includes:
# Saving and scanning email attachments or web downloads rather than selecting the option to open them directly from the source.
# Scanning floppy disks, CDs or DVDs for viruses before opening any of the files.

What happens if the software finds a virus?
Each package has its own method of response when it locates a virus, and the response may differ according to whether the software locates the virus during an automatic or a manual scan. Some times, the software will produce a dialog box altering you that it has found a virus and asking whether you want it to clean the file (to remove the virus). In other case, the software may attempt to remove the virus without asking you first. When you select an anti-virus package, familiarize yourself with its features so you know what to except.

Which software should u use?
There are may vendors who produce anti-virus software, and deciding which one to choose can be confusing. All anti-virus software performs the same function, so your decision may be driven by recommendations, particular features, availability, or price. See the references section for a link to a list of some anti-virus vendors.
Installing any anti-virus software, regardless of which package you choose, increases your level of protection. Be careful, though, of email messages claiming to include anti-virus software. Some recent viruses arrives as an email supposedly from your IPS's technical support department, containing an attachment that claims to be an anti-virus software. However, the attachment itself is in fact a virus, so you could become infected by opening it.

How do you get the current virus information?
This process may differ depending what product you choose, so find out what your anti-virus software requires.
Many anti-virus packages include an option to automatically receive update virus definitions. Because new information is added frequently, it is a good idea to take advantage of this option. Resist believing email chain letters that claim that a well known anti-virus vendors has recently detected the "worst virus in history" that will destroy your computer's hardware. These emails are usually hoaxes. You can confirm virus information through your anti-virus vendor or through resources offered by other anti-virus vendors.
While installing anti-virus software is one of the easiest and most effective way to protect your computer, it has its limitations. Because it relies on signatures, anti-virus software can only detect virus that have signatures installed on your computer, so it is important to keep these signatures up to date. you will still be susceptible to viruses that circulate before the anti-virus vendors add their signatures, so continue to take other safety.

Computer BIOS Technology

BIOS or the Basic Input Output System, is a set of programs stored inside a ROM chip and put on the Motherboard. The main job of the program stored into this ROM is as it's name suggestion is to provide the computer user with a set of standard routines to take care of input/output form different input, output and storage devices connected to the computer.

This BIOS ROM is always available in the computer, so any user program ca access these routines for their input/output requirements.

The first PC BIOS was made by the IBM for their PC range of computer. The BIOS program being the copyright property of the IBM cop. PC compatible makers use the BIOS made by AMI, Award, Phoenix etc.

BIOS BASICS:
What is the BIOS?
BIOS is the acronym for basic Input Output System and it pronounced "bye-OS". It is a program stored inside a PROM chip on your computer.
This program lets your operating system and application programs communicate with the computer hardware and peripheral devices such as floppy disk, hard disk, printer, display adapter etc.
Reading the keystroke, displaying on the screen, reading/writing of the serial & parallel port, reading/writing to and from the floppy & hard disk etc. is done under the control of the BIOS.
The BIOS is a set of instructions or software stored inside a PROM (programmable Read Only Memory), PROM is a hardware, so a BIOS is not complete software nor a complete hardware that is the reason a new name "firmware" is used to describe the BIOS.
The term "firmware" is used to describe a software stored in red only memory. When the user program asks the BIOS to red the keyboard it is the job of the BIOS to read the keyboard in a proper manner, so as the data form the keyboard can be made available to the user program.
If you have two different computers, one having keyboard connection at I/O port 60 and the other having keyboard connection at I/O port 62, you don't have to purchase a different program for each of them.
Your program can just give the "read keyboard" command to the BIOS and it will be the job of the BIOS to read proper I/O port:

• Port 60 on the first computer and
  

• Port 62 on the second computer.

PC-BIOS Communication:
The computer or user program and the BIOS communicates with each other using something called interrupts.
Whenever the computer has to request for some information to the BIOS, computer generated an interrupt, and the BIOS will carry out a specific work such as reading the keyboard or displaying something on screen etc. according to the interrupt number.These interrupts are software interrupts and are different from the hardware interrupt generated by some devices to communicate to CPU. Just like hardware interrupt, when a software interrupt is received by the processor, the processor stops whatever it was doing and takes care of the interrupt. When an interrupt is received, the BIOS will search the interrupt vector table (IVT) for the address of the program that should provide the required services to the interrupting program. Once the address is found, BIOS starts execution of the interrupt service routine a program that provides the requested service to the interrupting program. After finishing the interrupt service routine the BIOS will routine back to the old process that has initiated or called the interrupt routine. The Interrupt vector table is located at the lowest RAM memory address that is at the address 0000 at segment 0000 and contains 4byte for each interrupt number. This interrupt Vector Table (IVT) is loaded from the BIOS ROM to the RAM at the tome of system startup. Loading the address from the ROM to the RAM is done so that if the user wants to change the interrupt service routine's provided by the BIOS, he can do so by changing the routine's address in the RAM vector table.
Other BIOS Functions
other than the I/O function explained so far the BIOS contains two more modules

• Power on self test and
  

• Bootstrap loader.

POST (Power On Self Test):
What is POST?
This is an abbreviation of Power On Self Test. It is a set of diagnostic programs loaded from the BIOS ROM during the system power on time. This program ensures that in a computer all the major system components are present and are working properly. This POST program checks the processor, memory, support circuits and other devices connected to the computer when the computer is first powered on. If this routine finds any error or fault during this POST, the error is informed to the user as an error beep or as some error message on the screen. Some errors called nonfatal errors allow user to continue, whereas fatal errors will not allow the POST to continue until the problem is rectified. Once the POST routine is executed successfully, BIOS goes to the boot process.
Bootstrap Loader:

After the POST routine, BIOS continues with a program called bootstrap loader. It is the job of bootstrap loader to load Operating system (OS) from the floppy disk, hard disk or CD-ROM into the computers main memory (RAM). Unless the boot process is completed successfully i.e the OS is copied from storage device to the main memory, user cannot use the computer.
A successful transfer of the OS into the RAM or the boot process is indicated by displaying the DOS prompt such as A:\> or C:\> on the computer monitor. If you have windows 95/98/ ME etc. installed in your system then instead of DOS prompt, you will directly go to the Windows screen.

Generations of computers

Evolution:
The history of computer development is often referred to in reference to the different generations of computing devices. Each generation of computer is characterizes by a major technological development that fundamentally changed the way computers operate, resulting, in increasing smaller, cheaper, and more powerful and more efficient and reliable devices.

First generations of computer(1940-1956):
The first computers used vacuum tubes for circuitry and magnetic drums for memory. They were often enormous in size taking up entire room. They were very expensive to operate and in addition to using a great deal of electricity, generated a lot of heat which was often the causes of malfunctions. First generation computers relied on machine language to perform operation and they could solve only one problem at a time. Input was based on punched cards and paper tape and output was displayed on print outs. The UNIVAC and ENIAC are examples of first generation computers. The UNIVAC was the first commercial computer delivered to a business Clint, the U.S census Bureau in 1951

Second generations of computers(1956-1963)
Transistors were used for circuity in second generation computers. Thar means vacuum tubes were replaced by transistors. The transistors was far superior to vacuum tube, allowing computers to become smaller in size, faster, cheaper, more energy efficient and more reliable than first generation. Second generations computers still relied on punched cards for input and printouts for output. Second generation computers moved from machine language to assembly language. E.g. IBM 401

Third generation of computers (1964-1971)
Integrated circuit (IC) was used instead of transistor in third generation of computers. Instead of punched cards and printouts, user interacted with third generation computers through keyboards and monitors and interfaced with operating system. They were smaller and cheaper than second generation computers. E.g IBM 360

Fourth generation of computers (1971-to present)
Microprocessor brought the fourth generation computers as thousand of integrated circuits were built onto a single silicon chip in 1981, IBM introduced its first computer for the home user, and in 1984 Apple introduced the Macintosh. All these computers became more powerful, they could be linked together to form networks, which eventually lead to the development of internet. Fourth generation computers also saw the development of GUIs, the mouse and hand held devices.

Fifth generation of computers (present and beyond)
Fifth generation computers based on the artificial intelligence, are still in development, through there are some applications such as voice recognition, that are being used today. Quantum computation and molecular and nanotechnology will radically change the face of computers in years to come. The global of fifth generation computing is to develop that respond to natural language input and capable of learning and self organization.

Operating system

What is an operating system ?
An operating system is system software that acts interface between computers system and user. Operating system helps to make communicatinos between users and computers. If there is no operating system , there is no interact between users and computers.
The application programing like word processor, spreadsheet, compilers, web browers work on the top of operating system. In other words, OS provides platform to run the application programs. The platform may be GUI or CUI. The OS controls and co-ordinates the uses of the hardware among the various applications programs for the various users.
We can also view a computer system as consisting of hardware, software and data. The OS provides the means for purpose use of the resources in the operation of the computer system. An OS is similar to government. Like government, it performs no useful function by itself, it simply provides an environment within which other programs can do useful work.
Operating system exists because they offer a responsible way to solve the problem of creating a usable computing system. The fundemental goal of computer system is to execute user programs and to make solving user's program easier. Towards this goal, computer hardware is constructed. Since bare hardware alone is not particulary easy to use, applications program are developed. These programs require certain common operating system such as controlling the I/O devices. The common function of controlling and allocating resources are then brought together into one piece of software, the operating system.

Its the time of sixthsense

what is sixthsense ?
Sixthsense is a gestural interface that combines physical world with digital information and lets people use natural hand gesture to interact with that informations.
The sixthsense is the several applications that demonstrate the usefulness, visibility and fecibility of the system. The applications lets the user nevigate a map display on a nearby surface using hands guestures, supported by multi-touch based system, letting the user zoom in, zoom out or pan using intuitive hand movements. There is a drawing applications which lets the users to draw any surface by tracking the fingertip movements of the user's index finger. Free hand of the users are also recognized by sixthsense. For example it implements a gestural camera that takes photos of the scene the user is looking at by detecting the "framing" gesture. The user can stop by any surface or wall and flick through the phots he/she has taken. Sixthsense also lets the user draw icon or symbols in the air using the movement of the index finger and recognize those symbols as interaction instructions. For example drawing a magnifying glass symbol taken the user to the map application or drawing an '@' symbol lets the user check his mail. The sixthsense system also augments physical objects the user is interacting with by projecting more information about these objects onto them. For example a newspaper can show live video news or dynamic information can be provided on regular piece of paper. The gesture of drawing a circle on the user's wrist projects an analog watch to effectively tell the time.

Notebook Sony Vaio P VGN-P15G

Sony insists the vaio P is not a notebook, but a premium "pocket style Pc". The emphasis is clearly on aesthetics and portability, with a super-slim design and high quality glossy paint finish.
The unique shape allows you to slip a Vaio P into coat pocket or trouser pocket. It's less than 2cm thin, and only slightly wider and deeper than business envelope. Externally, you'll notice the perfectly rounded corners and smooth lines. Even the underside is free of stickers, labels and screws. Around the edges are the power and Wi-Fi switches, two USB ports, an earphone socket, a custom port for expansion, and one slot each for SDHC and memory stick cards limiting, but manageable.
Opening the lid reveals large roomy keyboard. The keys are well spaced, expect for the minuscule right [shift] key and the cramped arrow key cluster. Unfortunately they are a bit too mushy and since there's no wrist rest, the lower lip where the cursor buttons sit obstructs the entire bottom row.
The track point is well positioned and you can ta it lightly to register ca click. Above the keyboard lie two slots fo the speakers, which quite frankly are awful. A mic and VGA Webcam are integrated.
The screen measures eight inches, pretty normal for a notebook-class device, but has a crazy resolution of 1600 x 768 over twice as wide as it is tall. This kind of horizontal resolution is greater than most 19inch desktop monitors! Sure it plays HD videos, but all those pixels are crammed into almost no space at all. icons and buttons are minuscule, and even regular texts on screen is impossibly tiny.
A shortcut buttons brings up a dedicated media interface which is designed to look and feel like the PSP's Xross Media Bar. Pressing the same buttons while the Vaio P is off brings up Instant Mode, an instant on OS which lets you access stored media files and browses the Web as well.

Open source

What is open source ?
Open source is a methodology or approach towards the design and development of software with the intention of giving the user access to the source code, i.e. if you use open source software, not only will you able to use it, you will also be able to see how it works, debug it, modify it and redistribute it. Actually the term open source has been center stage of a David vs Goliath fight in the software community. Be it windows vs other operating system, or Internet Explore vs Mozilla. Open source has been the rallying point of the so called 'resistance' to the proprietary regime. To elaborate and make the difference more clear, imaging the simplest entry level C++ programing, the one that says "hello world". If the program was proprietary (non open source), you would merely have access to the EXE file that upon execution would give a window with "hello world" written in it. However if the program is open source, you will also be given access to the code that the EXE file is compiled from, namely.
#include
void main ()
{
count<<"hello world";
}
Hence not only you will be able to use this program for the pleasure of hearing a "hello world" from your computer, you will be able to modify this code to allow it to say more than just that.This example of course was overly simplest. Even if the program had been proprietary, anyone could recreate it making it immaterial whether it was open source or not. However in this era of programming that runs tens of thousand of lines of code, with complex algorithms and databases forming an integral part of the system, it is impossible to recreate the code from observing how a program functions. The open source Initiative, an organization committed to promoting open source users the open source definition in order to determine if a software is open source or not. This definition, among other things specifies requirements of the license such as preventing discrimination against fields of endeavor. One must not forget that there is a core difference between open source and free software. While they both embody the same core idea, the former still allows the commercial utilization of the code with the motive of profit. Many companies such as Red Hat gain significant revenues from sale, distribution, maintenance and consultancy services provided on open source software.

computer hacking

What is hacking?
The act of remotely accessing someone's computer to steal their private files would be hacking. Note the words "steal their private files", what if that conditions was removed? Or what if you are simply accessing your own computer or that of a friend's to help him/her out?
Like the driver of a car would be called a driver, whether it is done by someone with the car owner's permission, by the car owner himself/herself or without the car owner's permission. Driving is driving regardless of the ethics, the context is irrelevant. Similarly a person is a hacker whether they are bypassing their own computer's security to access their own files, or doing it on someone Else's computer without the permission of the owner.
A person hacking into a computer to test its security is a hacker who is a security expert, a person hacking into a computer to steal passwords is a criminal. Here the context decides the legality and ethics of the act, and the person is accordingly labelled a "security experts" or "criminal", but he is a hacker nonetheless.
Hacking is an expression of our own curiosity, "how does it work?", "why can't i access it?",
"what happens if i give 400 volts instead 220?" It is simply the result of our drive to understand the things around us.Often people are curious about things which may cause them or others harm, such as child curious about an electricity socket, or an teen curious about drugs. A computer hacker is one who is curious about the working of computers and software. While many people are happy treating their computer like a black box, where they merely feed in data and get in return, others strive to break in and understand how it works, and why it works that way often, instead simply accepting things the way they are, they will look for ways to make things work the way they want. While this may be considered juvenile, hacking into someone's computer as you are responsible enough to respect their privacy.

Computer OSI several layers model

The year 1980s the Europeans-dominated International Standards Organization(ISO) networking suite. OSI has two majors components an abstract model of networking and a set of concrete protocols.
Parts of OSI has influenced Internet protocols development, but none more than the abstract model itself, documented in OSI 7498 and its various addenda. In the model, a networking system is divided into layers. Inside each layer, one or more entities implement its functionality. Each entity interacts directly only with the layer immediately beneath it, and provides facilities for us by the layer above it. Protocols enable and entity in one host to interact with a corresponding entity at the same layer in a remote host.

The seven layers of OSI Basic reference Model:
1) The Physical Layer describes the physical properties of the various communications media, as well as the electrical properties and interpretation of the exchanged signals. It defines the size of the Ethernet coaxial cable, the type of BCN connector used, and the termination method.
2) Data Link Layer describes the logical organization of data bits transmitted on a particular medium. It defines the framing, addressing and check summing of Ethernet packets.
3) Network layer describes how a series of exchanges over various data links can deliver data between any two nodes in network. It defines the addressing and routing structure of internet.
4) Transport Layer describes the quality and nature of the data delivery. It defines if and how retransmissions will be used to ensure data delivery.
5) Session Layer describes the organization of data sequences layer than the packets handled by lower layers. It describes how request and reply packets are paired in remote procedure call.
6) Presentation Layer describes the syntax of data being transferred. It describes how floating point numbers can be exchanged between hosts with different math formats.
7) Application Layer describes how real work actually gets done. It implements file system operations.

The original Internet protocol specification defined a four-level model,and protocols designed around it(like TCP) have difficult fitting neatly into the seven-layers model. Most newly designed use the seven-layer.

OSI Basis Reference Model has enjoyed a far greater acceptance than the OSI protocols themselves. There are several reasons for this. OSI's committee-based design process bred overgrown, unimaginative protocols that nobody ever accused of efficiency.

Computer Antivirus

Kasper-sky Anti-virus for Mac

Kasper-sky Anti-virus for Mac has been developed to meet the specific security requirements of Mac users who know the value of the data stord on their computers, along with the need to keep them running smoothly. As one of the most successful specialist software security companies in the world, you can trust Kaspersky's award winning technologies to protect your, music, photos, file and sensitive information, and prevent you passing malware threats on to friend and colleagues when exchanging information with other types of computers. Kasper-sky Anti-virus for Mac is based on Kasper-sky Lab's new anti-virus engine which dramatically increases system scanning speed thanks to improved processing of objects and optimized use of system resources, particularly on dual and quad core processor platforms.The new products of mac OSX (version 10.4.11 and higher) combines the advantages of the new anti-virus engine with a security apporach that is based on protecting home or coporate networks from multipal form It threats. Kasper-sky for Mac protect against Mac OS viruses, worms, and Trojans and as well as combating similar threats for Windows and Linux operating systems.
In order to protect mixed networks more effictively, Kasper-sky Lab's new product has access to the company's global antivirus database that includes information on more than 20 million malicious programs for a range of platform. The Kasper-sky anti-virus database for Mac are uploaded hourly. This ensures that the users are protested against the very latest malicious programs that appear in large numbers. Kasper-sky anti-virus also protests shared folders on virtual machines which are gaining in popularity with both corporate and home users. The new products includes an automated model for operating with applications, which means the program takes decisions automatically and doesn't bother users with unnecessary requests.
Kasper-sky anti-virus for Mac was especially designed to meet the needs of this operating system, offering complete comparability with all versions of the OS from 10.4.11.

computer network

INTRODUCTION:
Computer network is interconnection between computers through electronic circuits and wireless transmissions of various designs and technologies for the purpose of exchanging data or communicating information's between them or their users. Networks may be classified according to a wide variety of characteristics.
A computer network allows sharing of resources and information among devices connected to the network. The Advanced Researcher Project Agency (ARPA) funded the design of the advanced Research Department of Defense. It was the first operational computer network in the world. Development of network began in 1969, based in the designs developed during the 1960s.

PURPOSE:
1) Facilitating communications. Using a network, people can communicate efficiently and easily via e-mail, instant messaging,chat rooms, telephony, videos telephone calls, and videoconferencing.
2) Sharing hardware. In a networked environment , each computer on a network can access and use hardware on the network. Suppose several personal computers on a network each require the use of laser printer. If the personal computer and a laser printer are connected to a network, each user can then access the laser printer on the network, as they need it.
3) Sharing files, data, and information. In network environment, any authorized user can access data and information stored on others computer on the network. The capability of providing access to data and information on shared storage devices is an important feature of many networks.
4) Sharing software. Users connected to a network can access application programs on the network.

CONNECTION METHOD:
Computer networks can be classified according to the hardware and software technologies that is used to interconnect the individual devices in the network, such as optical fiber, Ethernet, Wireless LAN, Home PNA, Power line communication.
Ethernet uses physical wiring to connect devices. Frequently deployed devices include hubs, switches, bridges and routers. Wireless LAN technology is designed to connect devices without wiring. These devices use radio waves or infrared signals as transmission medium. ITU-TG technology uses existing home wiring(coaxial cable, phone line and power lines) to create a high-speed (up to 1 Gigabyte/s ) local area network.

NETWORK CLASSIFICATION
1) WIRED TECHNOLOGIES
2) WIRELESS TECHNOLOGIES

1) WIRED TECHNOLOGIES:
* Twisted-pair wire the most widely used medium for telecommunication. Twisted-pair wire ordinary telephone wires which consist of two insulated copper wires twisted into pairs and are used for both voice and data transmission.
* Coaxial cable is widely used for cable television systems, office buildings, and other work sites for local area networks. The cable consists of copper or aluminum wire wrapped with insulating layer typically of a flexible material with a high dielectric constant, all of which surrounds by a conductivity layer.
* Fiber optical cable consists of one or more filaments of glass fiber wrapped in protective layer. It transmits light which can travel over extended distances without fiber optical cables. Transmission speed may reach trillions of bits per second. The transmission speed of fiber optical is hundred of times faster than coaxial cables and thousand of times faster than twisted pair wire.

2) WIRELESS TECHNOLOGIES:
* Terrestrial microwaves use Earth based transmitter and receiver. The equipment look similar to satellite dishes. Terrestrial microwave uses low gigahertz range which limits all communications to line of sight. Path between relay stations spaced approx 30miles apart.
* Communications Satellites uses microwave radio as their telecommunications medium which are not deflected by Earth's atmosphere. The satellites are stationed in space, typically 22,00 miles above equator.
* The wireless Web refers to the use of World Wide Web through equipments like cellular phones, pagers, PDAs, and other portable communication devices.

computer internet

In this modern era most of the people have heard about Internet or known about it. Only some of the people have never heard of internet, however most of them have either used the internet occasionally or frequently. To know that the internet has attracted an enormous amount of attention past few years it does not take time to know about internet.

what would be the cause of thousands of companies millions of people and virtually every majors countries investing millions of dollars into internet?what truly is all this fuss about?
They say that its because of the speed of wide variety of information's found on the net and it is easy to access and publish information's on the internet.

BENEFITS: The internet speed vast resources and its ability to directly communicate with others around the world. Internet uses the quickness of computers to transmit its data, information can travel at tremendous speed. The inter sues hundreds of thousands of computers all connected to each other to store vast amount of information. And because the internet allows for individuals to have specific electronic mail address, people can easily communicate with one another from any corner of the world.
Internet is considered by many to be superior to the best and biggest libraries in the country. Internet ability to deliver this vast amount of information has drawn even more users. Instead of reading a medical breakthrough in next month's journal, it can be published on the internet instantly. Breaking news events can be published almost immediately after the event occurs. People don't have to wait until the morning paper to read about an event. Part of this internet has helped to make the internet a technological breakthrough.
How did the internet begin?
The history of Internet is not complicated not that long. 25years ago the internet began as an experiment of U.S Defense Department. The fact it was not originally designed for the public's personal use. Originally the goal of the internet was establish a system to safeguard the exchange information among different government agencies in the event war. Without a computer or person controlling the internet, the enemy could not destroy means of communication with just one military strike. Today this unique features of the internet remains constant and part of its success. No one person or organization controls or heads the internet. It is basically hosted by thousands of individual computer have registered with NSF(National Science Foundation) for an Internet address.

Computer

In this modern era as the internet and networks are rapidly developing computer viruses are disturbed rapidly and intensively. In every single day several new viruses are capable of damaging your computer system. The computer anti-virus specialist are working hard to update there softwares against new viruses as soon as possible. Viruses can get inside the computer in different ways that is why there is no simple method to protect computer system. But some series of measures can give you protection against the viruses infections. Some few steps to protect MS Windows based computer system from viruses.

1. REGULAR BACKUPS: There are no absolutely safe ways of protection. Regularly viruses creators find holes in new computer products for them to infect computer system. There are some dangerous viruses that can considerably damages data files or even erases entire file system. Making regular backup of your data file to separate file storage device. Hard drives,flash cards, compact disc or other file storage device which you choose can be separated. To make it easy for backups you can use automatic backup softwares.

2.PROTECTING NETWORK CONNECTIONS: You can protect your computer network connection with firewall, it is the software which blocks suspicious potentially dangerous connections to prevent viruses from networks to get into your computer system. Enabling ways of firewall are as follows:
1) Go to control panel, double click networking and internet connections, and then click network connections.
2) Right click the connection on which you would like to enable firewall and click properties.
3) On the advanced tab, check the option to protect my computer and network.
4) Installing antivirus softwares which will scan your computer system searching and erasing viruses on a regular basis. Some antivirus products for windows system are Kaspersky, Mcafee, Northon antivirus.
5) Updating regularly is very important, Windows XP has automatic updates built in its system.
6) Don't install suspicious software.
7) Protecting your computer system with passwords.